What state do I file my taxes?

[Mags3]

In 2019, I was an out-of-state graduate student in New York City but I didn't make any money during the academic year. Over the summer, I lived in Bel Air, Maryland and worked in D.C. My job was a paid internship where I made $3,600 and received a 1099. However, my permanent residence was still where my parents live in Georgia. So, where do I file? 

[Hal_Al]

Georgia only, unless there was state  withholding, on your W-2, for another state.  DC is reciprocal with all other states.  You only pay tax to your home state. The temporary residences in NY & MD are irrelevant, since you didn't earn money there.